The present invention relates in general to devices for making electrical wires, and in particular to a device of the type which supports on a supply rod a succession of resilient split rings each provided with a marking symbol on its outer surface, whereby the front part of the rod extends into an application shoe which is formed on its lower surface with a recess which is supplied on a wire to be marked, and the marking split ring is shifted over the application shoe onto the wire.
Markers of this type are known, for example from the German Pat. No. 26 55 958, and are used for applying marking rings of plastic material onto electrical wires. For this purpose, the recess of the application shoe or foot at the end of the supply rod is placed on the wire to be marked and subsequently one or more plastic rings with the marking symbols are shifted over from the supply rod via the shoe onto the wire. When the plastic split rings slide over the diverging application shoe, they are sufficiently opened out at their slits to resiliently engage the wire.
In order to reduce storage expenses for such plastic marking rings and the corresponding supply rods, the rings of certain inner diameter are normally used not only for a wire of this particular diameter but for a whole range of wire thicknesses close to the diameter of the marking ring. In determining the applicability of a marking ring of a particularly inner diameter to a certain range of wire thicknesses, it must be taken into consideration what is the permanent residual expansion of the ring after its sliding over the application shoe, and if the sliding movement of the ring on the wire should be prevented.
Accordingly, the inner diameter of the marking ring is determined by the outer diameter of the thinnest wire of the group, the size of the application shoe is determined by the diameter of the thickest wire of the group because even the thickest wire should fit in the bottom recess of the shoe. It is this maximum dimension of the shoe which brings about a problem resulting from the enlargement of the plastic ring when shifted past the broadest part of the shoe. This enlargement causes a relatively large permanent extension of the ring, and consequently the applicability of the shoe for use with wires of smaller diameters is impaired.